Baker's yeast (Saccharomyces cerevisiae) cells were magnetically modified with magnetic iron oxide particles prepared by microwave irradiation of iron(II) sulfate at high pH. The modification procedure was very simple and fast. Both non-cross-linked and glutaraldehyde cross-linked magnetic cells enabled efficient sucrose conversion into glucose and fructose, due to the presence of active intracellular invertase. The prepared magnetic whole-cell biocatalyst was stable; almost the same catalytic activity was observed after 1-month storage at 4°C. Simple magnetic separation and stability of the developed biocatalyst enabled its reusability without significant loss of enzyme activity.
Significance and impact of the study: Magnetic whole yeast cell biocatalyst containing intracellular invertase in its natural environment has been prepared. Magnetic properties enable its easy separation from reaction mixture. Magnetically modified Saccharomyces cerevisiae cells have been used for invert sugar production, hydrolysing sucrose into glucose and fructose. The described magnetization procedure employing microwave-synthesized iron oxide microparticles is a low-cost and easy-to-perform alternative to already existing magnetization techniques.
© 2013 The Society for Applied Microbiology.